It is customary for certain kinds of documents, such as those used for marine navigation charts, drawings, and blue prints, to appear on large, flexible sheets of paper which may be rolled in tubular form or folded. Folding a chart or drawing is undesirable because the creases on which the document is folded often obliterate information through which the creases pass. Particularly is this true in those instances in which a chart or drawing is folded and unfolded numerous times over a period of months or years.
Maintaining a drawing or chart in rolled, tubular form is more desirable than folding it inasmuch as creases thus are not formed. However, when it is desired to use the drawing or chart it must be unrolled an amount sufficient to enable the desired area of the document to be viewed, and sometimes this requires unrolling virtually the entire document. When such a document has been partially or completely unrolled, difficulty is encountered in maintaining it in its unrolled condition inasmuch as it has a tendency to return to its rolled condition. Further, such an unrolled document is susceptible to being torn, particularly if it is subjected to winds such as those prevalent in boating.
An object of the present invention is to overcome the disadvantages referred to above.